The present invention is concerned with a device for severing a sparerib from a backbone, wherein the split backbone is conveyed inside a guideway, which is comprised of two guide plates and which delimits a wedge-shaped channel through which the sparerib projects in each case and a cutting device traverses past on the side of the ribs.
A cutting device of this type is known from CA 2,010,034, wherein a band saw crosses the path of conveyance of the sparerib. The band saw, as is well known, produces a wide cut of approximately 0.8 mm and, hence, high losses on the valuable spareribs. The waste material must be disposed of in a complex manner in accordance with the regulations. Also, in the above known device the spacing cannot be varied between the two steep-angled guide surfaces that are located at the input end of the saw. In these, the backbone with the ribs is held in such a way that the ribs are located in between and the backbone above them, thus defining the cutting plane of the saw in relation to the backbone. As a result, in the case of a thicker backbone, the cut is unnecessarily far away from it and a considerable amount of sparerib is lost. The band saw has the added shortcoming that it incorporates multiple moving parts, which require complex cleaning and maintenance.
It is the object of the invention to create a cutting device for spareribs that does not have the above shortcomings and results in minimal waste and losses while providing a simple design and safe operation.
This object is met in such a way that the cutting tool is a circular blade with a slicing or serrated edge, which is tapered to form a sharp edge and which is disposed close and parallel to the guide plates, whose distance from one another can be adjusted.
Advantageous embodiments will be specified in the subclaims.
The blade with its wedge-shaped finish, as compared to a band saw, operates as a rotating cutting blade, which pushes the separated areas apart without removing much material from the cut like a saw. The cutting losses are thus very minimal when a small serration is provided along the edge and next to zero when a smooth or slightly wave-shaped cutting edge is implemented.
The adjustability of the width of the guide channel because of the adjustability of one guide plate in relation to the other results in each case in an optimal position of the backbone in the channel that matches its thickness. In this manner the cut is performed close to the vertebrae in each case, and it prevents cutting into the side processes that extend from the vertebrae next to the ribs by a close margin, but no piece of the sparerib is lost.
The exact depth position of the backbone in the guide channel is ensured by a conveyor drive that exerts an elastic pressure and comprises a plurality of contact pressure wheels that are driven synchronously and can optionally be coupled, and which are held elastically in the direction toward the split surface of the backbone. The contact pressure wheels, of which there are preferably three, are positioned along the channel in such a way that at least one of them acts upon the backbone before the ribs enter into the cutting position, and at least one of them acts upon the backbone after it leaves the cutting area.
The conveyor belt with its guide plates starts in front of the conveyor wheels with a covered safety area and with an insertion area in front of the former, where the backbone with the attached ribs is placed, inserted, into the channel.
To render the insertion simple, the guide and support plates are positioned horizontally and the circular cutting blade is disposed horizontally below it.
In an advantageous embodiment the cutting blade enters with its edge into a groove in the guide plate so that the cutting blade together with the closely adjacent groove leg performs a shearing function. The circumference speed of the blade is only approximately 5 times greater than the conveyance speed and thus considerably slower than that of a saw.
What remains on a backbone after the tenderloin has been cut out are the curved true ribs, of which 100 to 150 mm for the formation of the spareribs are left on the backbone to be severed in each case, and adjoining the same is an area with false ribs, which are shorter and virtually not curved. Between the individual true and false ribs extends the valuable residual meat, which is to be rendered useable by the severing cut. In a preferred method, incisions are made into the residual meat in the transition area between the types of ribs and the backbone is then placed into the cutting device. The difference in length between the curved and straight ribs is utilized advantageously to separate the two rib sections after they have been severed in such a way that a separating wall is disposed at an appropriate height in the drop region for the rib sections. The deflector unit that is formed in this manner guides the curved wide spareribs and the narrow, shorter side pieces into different collection containers.
In an advantageous improvement of the invention, a conveyor belt with a drive that transports the spareribs to a processing table is disposed in the end region behind the cutting device in lieu of a slide. The belt conveyor and its protection cover are advantageously mounted height adjustable on the stand of the cutting device in an easily removable manner, to permit an effortless cleaning.
In a further advantageous embodiment, severing shears are provided in the front inlet area to cut off the relatively small flap with the false ribs so that the cutting disk is used only to sever the real ribs. This eliminates the separation in the rear conveyance area. The severing shears are controlled with optical sensors that are adjusted to the transition area between the short and long ribs.